# Mosfet Vgs issues

I am building a MOSFET bridge to make sure my signals arrive at the load in the proper polarity regardless of the input polarity. My problem is the $$\V_{gs}\$$ voltages on the MOSFETs are at or exceed 20 V, this is the maximum $$\V_{gs}\$$ MOSFET I can find. What can I do to lower my $$\V_{gs}\$$ while still passing 11 V signals and having the proper MOSFETs turn on/off at the right times?

Here is the circuit. Battery voltage is 11 V, and op-amps are ±10 V, any lower on the op-amps causes MOSFET M3 to saturate.

EDIT: added a more clear schematic. N-channel MOSFET $$\V_T=1\$$, p-channel MOSFET $$\V_T=-1\$$. Link to the online circuit simulation simulation

I need to keep my $$\V_{GS}\$$ below 20 V, and the opamp rail voltages must be equal between opamps. The voltage source can swing between ±10 V. The common is always common, so just put a negative voltage into the value box on the simulator.

• You may get more responses if you draw your schematic more clearly: include designators for every component, flow signals from left to right, and specify a ground node. – The Photon Jul 10 '12 at 20:11
• Agreed, it's pretty unreadable as it is ;-) – Oli Glaser Jul 10 '12 at 20:32
• Edited post to make the situation more clear. Check out the simulation link for an online simulation. – Z2012 Jul 11 '12 at 15:43
• What about the diodes that are inside the mosfets, it looks like they will be a problem – Z2012 Jul 11 '12 at 23:29
• Won't OA1 just saturate at the positive rail? – Scott Seidman Oct 9 '12 at 18:57